Method of and apparatus for vulcanizing



R. H.A1cHEs0N.

METHOD OF AND APPARATUS FOR VULCANIZI'NG. APPLICATION FILED FEB=I61 1921.

2 SHEETS-SHEET l.

mventoz R. H. ACHESON. METHOD 0F AND 'APPARATUS FUR VULCANIZINGY APPLICATIQN FILED FEB 16, 192|.

1,388,138. PatentedAug.16,1921.

2 SHEEI S-SHEET 2,

Houra,

PATENT OFFICE.-

ROBERT H. ATCnEsON, OE PROVIDENCE, RHODE ISLAND, AssreNOR'TO IBEX RUBBER CORPORATION, or JERSEY CITY.. NEw JERSEY, A CORPORATION or DELAWARE] METHOD .0F AND APPARATUS FOR VULCANIZING.

Application led February 16, 1921.

To all w kom it may concern Be it known that I, ROBERT 'A'roHEsON, a citizen of the United States, resi-ding at Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Methods of and Apparatus for Vulcanizing,

of which the following is a specification.

This invention relates to certain new and useful improvements in apparatus for and method of molding and vulcanizing hollow articles more particularly pneumatic tubes such as those used in'tiresfor motor vehicles; and the object of this invention is to provide simple and effective means whereby such hollow articles, more particularly tubes of plastic or unvulcanized rubber or rubber compound, may be positioned in a mold and vulcanized without forcing the stock out through the joints of the mold.

It is found in practice in the use of a vulcanizing press of the present character that in Vulcanizing rubber tubes of a size ordinarily used for pneumatic tires and which are usually constructed of rubber or rubber compound without a stil'ening layer of fabric, that the area of the tube is so great that if a Vulcaniz-ing pressure of steam were admitted to first enter the tube while soft, that such a heavy pressure would produce two effects; first, its heat would tend to immediately soften the rubber; and second, the heavy pressure would have a tendency to open or spread the mold at the joint and force the softened material out through the joints thus destroying the tube.'

To obviate this detrimental effect upon the tube I first admit a comparatively low pressure-of air, preferably cold air into the tube for a short period which serves to first expand the tube in the mold and second, to

cool the material and prevent it from melb ing or becoming softened until after the outer surface has been somewhat hardened by being partially cured, after which I may admit` steam pressure into the tube vof a temperature sufficient toicomplete the curin action.

ith these and other objects lin view,.the invention consists of certain novel features' of construction, as will be more fully de scribed, and particularly pointed out ln'the l ber 11 which 1s supplied with steam-at the appended claims.

Specification of Letters Patent.

Patented Aug. 165 1 921;

serial No. 445,533.

Fig. 2 is a plan view of the mechanismillustrated in Fig. 1.

F 1g. 3 is an enlarged view` of a portion of the upper heating chamber sectioned on lino 3 3 of Fig. 2, looking the direction of the arrow. Y

Fig. 4 is an enlarged section on line 4-4 of Fig. 2, through the steam heating chambers, showing the 'same closed upon a mold,

which latter is in operative position between them;

As is well known in the art-'the usual' l method of forming pneumatic inner tubes for automobile tires, is to first make up the tubes in long lengths on a pole which lengths are wound with fabric and subsequently baked or vulcanized in an 'oven after which they are cut into the desired lengths, bent into ring form and their ends abutted or lapped and cemented together all without the use of a mold, which is a comparatively long andexpensive operation and by which construction thev abutting ends are not vulcanized and are therefore the weakest part of the tube. In some other casesr it is known that the smaller sizes of tubes such as bicycle tires and the like which contain a stifenxing layer of fabric have been vulcanized in circular molds.

e My present invention contemplates the' constructing of tubes even the largest sizes employed in automobile tires .by first taking van unvulcanized, tube of rubber or rubber compound which usually formed without a stiffening layer of fabric, cutting the saine to the desired length, bending into' ring form and abutting or lapping the ends and then inserting this tubular ring into a lsplit circular mold and applying a vulcan- With reference to the drawings, 10 desig nates the upper platen of the vulcanizing press in which is formed an annular chamto form a tire tube of the desired diameter 'surethrough the. supply pipe 12, and13 designates thelower. chamber member which is supplied with ysteam of the necessary vulcanizing temperature through the pipes 14.

mounted on a table 15 which latter is supf ported on-a hydraulic piston-lin the cyl- 'inder 17 whereby this lower chamber may be made to drop to permit'the positioning -Y of the mold member 18 between said upper and lower heating chambers..

This vmold is preferably constructed of 4two registering. ring `members y19 and 2() which is provided' between them' with an an nular lrecess 21 for the reception of the tube I 22 lto be vulcanized. Thesetwo ringmeml bersv are'shownl-as being hinged together at 23. and provided 'at their-'front edges with 'this' moldmay vloedrawn out upon tracks 25* an roperating vhandle'i'nember 24 by which f upon which it is deposited when-the lower I .i platen is'droppedl and this. handle iS 21150 I ,adapted to raise the upper half of the mold 'having' been and swing it u upon its hinge 23` to permit the ready placmg of the tube therein to .be vulcanized and its removal therefrom after tion. v.

Before the tubeis inserted into the mold "I preferably fix the usual hollow lstem 26 into the tube vand Iconnect to this stem a H valve member 27 f which is provided with a lower endof "which member may be seated' 1-. and supportedat 30 on the inwardly pro- 'j ecting portion 3 1 ofthe lower mpldring 19.A

'In order to admit pressure of either air or steam into the tube afterhaving been positione'd in the'mold and the .mold positioned between its upper and lower heating cham bers 1 and ,13, .I have constructed a iiveway channel headme'mber' 32 which ispro-` f videdwith :a lthreaded stem 33 projecting 45 formed on the innersurface of the `up-per through the annular' hole infthe boss 34 platen 10v V'andin whichthis head member vTo one side of this head isf connected the steam pipe 137' which leads from` the upper steam chamber 11 through the valve 38. To

the other side 'of the head is vconnectedthe air-feed ipe 39- leading from the pressure tank 40 t roughthe valve 41. To the upper end of thishead is connectedv the pressure indlcator 42 to indicate the pressurein'the -tube and to the rear of thehead is' connected the discharge pipe 43 controlled' by the valve 44all. of which openings communicate with the central passageway 45 Vthrough the-stem which communicates with the passageway 29 in the'valve'me'mber 27 when the Ymold is in operative position.

'Inoperating the apparatusl first depositl submitted to a'- vulcanizing ac- 1,388,1se .l

has been previouslymade up into ring form and slightly inflated, the mold having been previously drawn from the heating chamybers 10 and 13 into the position illustrated `This lower 'platen is shown as being.-v

or. piston 16 thus raising the lower chamber and forcing the mold up against the upper vchamber'lO which at the same time automatically completes the connection between the valve member 27 and the five-way pressureesupply head 32. l next open valve 41 and' admit a comparatively light pressure,

say thirty pounds, more or less, preferably of coldair from the tank 401into the tube to expand the same against the walls of the mold, which cool air prevents the tube from melting or softening and so. revents it from being blown out through t e joint` in the mold. f

...In Athemeantime'ihe highly steam heated chambers 11 and 13 'are heatingA the tube through the walls of the mold and so pro-- ducing a partial vulcanizing eiiect upon its outer surface'.v

It has been oundin practice that if the full pressureof steam were first admitted -to this tube before its outer surface'had'been partially'.vulcanized-.that this heavy pressure admitted to solarge an area would spring the members of the mold apart' and open the .jointsi between them. and as the heat due to sucha pressurel would soften or melt the rubber compound vthe -pressure would force this softened material out through the'jointvand so completely destroy .pressure through the `feed pipe 46 to the ram l the tube; but vit has'beenl found in practice that by irst 'admitting a comparatively low pressureof cool air' into the tubeand permitting this low. pressure tov simply expand the tubein its mold and hold it firmly out against the heated ringsfor a short time or -until the outer surfacecan be partially cured or. hardened the tube will then stand the 'full pressure 'of steam which is necessary for vulcanizing the.` same on its inner surface and. socomplete the curing action. After the tube has been subjected to the .vul-

canizing heatv for a predetermined period I close valve 41 and .shut oil' the pressure of air which is retained in the tube.A I then open valve 38 admit 'the' full steam pressure. of pounds, more r\less,' from the cham'- be'r 11 directly into the tube to mix with the' air therein contained, whichV serves to cure the inner surface and vcom lete the proper vulcanizing of the tube, t e whole operation'. requiring but a few minutes. After the time. for vulcanizing has expired it is only necessary to close valve 38' and open valve 44 permitting the pressure to escape after which the Alower platen is droppedv the mold drawn out from the press v the upper steam chamber into .the tube,but

and opened, and the tube removed in a ished condition, the apparatus then being ready to repeat the operation upon anotherv .steam linto the tube without exhausting the tube. v

I have shown and described an arrangement by which steam may be admltted from steam may beconducted from any suitable source t'o` the tube.

In some instances 1t may be fo un'd desir able to admit a low pressure of steam to .the tube in the irst instance, insteadv of primarily admitting a pressure of air and in which former case it vis onlynecessary to openvalve 38 slightly-or suiiiciently to ad-` lmit just steam enough -to properly inflate i the tube in the mold and thepressure ad- Y' mitted ma be visibly determined by the gage 42. fter the tube has been partially vulcanized and hardened somewhat on the outside, the ull pressure may vthen be ad# mitted by fully opening the control valve' to complete the vulcanizing-of the-tire-.on its inside. v Having thus described one illustrative emknown to m'e for carrying out my method,

I desire it to be understood v'that although specic terms are employed, they are .used in a generic and descriptive sense and not for the purpose of limitation, the scope-of the invention being defined and limitedonly by the terms of the appended claims.

I claim: 4, 1. A tube vulcanizer comprising a mold for 'the tube having a single communicatf ingopening thereinto, means for .heating the mold, a single hollow stem extending through sa1d opening and communicating w1th said tube therein, means for communi'- eating with an air supply and connected to said stem for -admitting air pressure intov said-tube to expand the same in said mold,` x andmeans communicating with a steam supply also vconnected to saidstem, whereby a 1 vulcanizing pressure of steam may 'also be .intot subs uently admitted to the confined air in the tu e through said stem to vulcanizethe interiorl of said tube.

2. An improved method of vulcanizing a tube which consists in placing the tube in a.

mold applying a vulcanizing heat to the mold, vadmitting a pressure tube to expand it in the mold and subse-A quentliy; admitting a curing `pressure of steam e tube without exhausting-the a1r I i therefrom.

3. An improved methodiofvulcanizing va-y compounded rubber tube which consists in making the tube into ring form, placing the.v tube in a mold, applyingyavulcanizin'g heatV to the mold, admitting a comparatively light pressure lof air` into the tube for a prede-l of air into fthe'.

venter the tube inlsaid mo by which the pressure 'in the tube may be termined period to expand the tube in said Y mold, subsequentlyshuttingoff said air-pressure and 'A admitting a curing pressure of air therein contained. .4. An improved 'method of vulcanizing a com ounded rubber tube, which consists in placmg the tube in a mold, positioning the mold between steam heated chambers ad-v mitting an expanding pressure of cold air .into the tube while the exterior of the tube being .partially cured and subsequently shutting off the air supply and admitting vulcanl'zmg steam'fro'm one of said chambers to the interior of thev tube without exhausting the air in the'tube to complete the cur- 8.0 p

ing of the tube internally.

5. An improved method'. ofvulcanizing a tube which consists in making the tube into rin shape vandv lacing-the same in a similar y shaped mo d, applying a vulcanizingl members, a mold for aring-shaped tuberemovably mounted-between said members, a

pressure' supply pipe, ymeans-for automatically connecting saidsupply pipe into said it inthe mold'andsubsequently shuts 'ting olf .the air supply` and a tube through saidmoldfwhen both the latter and said members are inoperative position,

and means for controllin the pressure to enter the tube in the mol 7. VA vulcanizer "comprising two ring-v el i shaped heating members, n ieansff'or I'novingvv f one osaid members relative'itol thev other, a

ring-shaped tube-receivin mounted between saidV eating fr nembeI-.s',rf.` means for connecting the pressure supply` permanently to .one of .said members, mean for automatically connecting :the pressure supply .to the mold with that .of the fiixeV member whensaid members areclosed up0n i. the mold, and a' valve for' Controlling the,v

pressure to enter the tube in saidimold.

8. A vulcanizer A, comprising two ringone offsaid members relative to the other,` a ring-shaped tube-receiving mold "removably" mounted .between fsaid heating members,

means f'or connectinggthe presure supply to Q the Vmoldswith that' gofthe fixedl member j when Y.said members;arefclosedyupon.'the

the Apressure to` mold, a valve for, controllingd ,'anda gage determined. In testimony whereof I ROBERT H. AT cHEsoN.

moldY removablyll- 11o if vshapedheating members, means-for moving' v i' aliix my signature 

